Sodium Nitroprusside Functions in Browning Control and Quality Maintaining of Postharvest Rambutan Fruit

Surface browning after harvest is the primary constraint affecting the storage life and market circulation of rambutans. In this study, rambutan fruits were soaked in sodium nitroprusside at different concentrations and stored at 25°C for 8 days to explore the effects on postharvest quality and browning. The weight loss, browning index and superoxide anion radical, hydrogen peroxide and malondialdehyde contents of the treated fruits were reduced compared to those of the control fruits (soaked in distilled water). And fruits treated with sodium nitroprusside had a higher total phenolic content and lower polyphenol oxidase and peroxidase activity. In addition, compared with the control, the treated fruits exhibited higher phenylalanine ammonia lyase, ascorbate peroxidase and superoxide dismutase activities; titratable acidity; and soluble solid, vitamin C and protein contents, indicating high fruit quality. Overall, sodium nitroprusside treatment at 200 μmol L−1 demonstrated the most positive preservation effects. Therefore, sodium nitroprusside treatment, particularly at 200 μmol L−1, can be used as an eco-friendly, safe and convenient method for postharvest quality management and high-efficiency preservation of rambutan fruits.

Meso-Dihydroguaiaretic Acid Ameliorates Acute Respiratory Distress Syndrome through Inhibiting Neutrophilic Inflammation and Scavenging Free Radical

The pathogenesis of acute respiratory distress syndrome (ARDS) is very complex. Patients with ARDS still suffer high mortality rates. Infiltration and activation of neutrophils in lungs are critical pathogenic factors in ARDS. In this study, we demonstrate that meso-dihydroguaiaretic acid (MDGA), a natural lignan, inhibits inflammatory responses in human neutrophils and ameliorates ARDS in mice. MDGA inhibited superoxide anion generation and elastase release in various G-protein coupled receptor agonists-induced human neutrophils. However, MDGA did not alter superoxide anion generation and elastase activity in cell-free systems. These results suggest that the anti-inflammatory effects of MDGA are mediated by regulating cellular signals in human neutrophils. In consistent with this, MDGA suppressed phosphorylation of extracellular signal-regulated kinase and c-Jun N-terminal kinase in activated human neutrophils. Moreover, MDGA inhibited CD11b expression and adhesion in activated human neutrophils. Interestingly, MDGA reduced reactive oxygen species (ROS) generation but not superoxide anion generation in protein kinase C (PKC) activator-induced human neutrophils, suggesting that MDGA may also have ROS scavenging ability. Indeed, MDGA showed strong free radical scavenging activity in cell-free assays. Significantly, MDGA suppressed PKC-induced neutrophil extracellular trap formation. Additionally, treatment of MDGA attenuated neutrophil infiltration and lung damage on lipopolysaccharide-induced ARDS in mice. In conclusion, our results demonstrate that MDGA has anti-neutrophilic inflammatory effects and free-radical scavenging activity. We also suggest that MDGA has potential to serve as a lead for developing new therapeutics to treat ARDS.

Facile fabrication of TiO2/Bi5O7Br photocatalysts for visible-light-assisted removal of tetracycline and dye wastewaters

The emergence of persistent organic pollutants such as dyes and pharmaceuticals in the aquatic environment has created drastic concerns worldwide due to their toxicity and potential hazards to the environment. Accordingly, non-stoichiometric TiO2/Bi5O7Br nanocomposites were prepared by stirring method as a visible-light-effective photocatalyst for degradation of amoxicillin (AMX) and tetracycline (TC), as antibiotic pollutants, and Rhodamine B (RhB), methylene blue (MB), and malachite green (MG), as dye pollutants. The physiochemical properties of the samples were studied using FESEM, TEM/HRTEM, XRD, EDX, UV–vis DRS, FT-IR, XPS, BET, PL, photocurrent, and EIS analyses. The TiO2/Bi5O7Br (40%) photocatalyst performed superior to TiO2, Bi5O7Br, and TiO2/BiOBr (40%) in photodegradation of the studied contaminants. The degradation rate constants of AMX, TC, MG, RhB, and MB over the TiO2/Bi5O7Br (40%) photocatalyst were 18.2‒32.5-folds greater than pure TiO2, 1.6‒17.3 times higher than pure Bi5O7Br, and 1.4‒13 times larger than TiO2/BiOBr (40%), respectively. Quenching studies showed that superoxide anion radicals and holes had major roles in photocatalytic elimination of TC. Importantly, TiO2/Bi5O7Br (40%) nanocomposite showed robust reusability with high degree of TC removal after four successive photocatalytic recycles. This research introduces a cost-effective, efficient, and reusable visible-light-triggered binary system based on TiO2 for decontamination of medicinal and dye polluted wastewaters.

Effects of the Soil Moisture Content on the Superoxide Anion and Proline Contents in Soybean Leaves

Background: As an important source of feed protein, soybean is involved in the processing industry, food industry and other fields. Therefore, in recent years, the demand for soybean has increased and soybean planting areas have also increased. However, frequent droughts have a serious impact on soybean yield. Methods: During the flowering period, the soybean plants were subjected to drought treatments of different degrees (0-7 days without water). The superoxide anion and proline contents in the leaves were determined. Then, fitting curves were drawn between the soil moisture content and the superoxide anion and proline contents. Result: The effects of different soil moisture contents on the superoxide anion and proline contents in soybean leaves and the correlation between these contents were analyzed. According to the fitting curves, with a decrease in the volumetric water content of soil, the superoxide anion and proline contents in soybean leaves increased. The superoxide anion contents in drought-tolerant cultivars were significantly lower than those in drought-sensitive cultivars and the proline contents were significantly higher in drought-tolerant cultivars than those in drought-sensitive cultivars. The superoxide anion content in soybean leaves was positively correlated with the proline content in the soil volumetric water content range of 31.5% to 14.5%.

Tadalafil in Increasing Doses: The Influence on Coronary Blood Flow and Oxidative Stress in Isolated Rat Hearts

<b><i>Introduction:</i></b> This study aimed to assess the influence of different doses of tadalafil on coronary flow and oxidative stress in isolated rat hearts. <b><i>Methods:</i></b> The hearts of male Wistar albino rats (<i>n</i> = 48) were retrogradely perfused according to the Langendorff technique at gradually increased constant perfusion pressure (CPP) (40–120 mm Hg). Coronary flow and oxidative stress markers: nitrite oxide (NO) outflow and superoxide anion production in coronary effluent were measured. The experiments were performed during control conditions and in the presence of tadalafil (10, 20, 50, and 200 nM) alone or with Nω-nitro-L-arginine monomethyl ester (L-NAME) (30 μM). <b><i>Results:</i></b> Tadalafil administration significantly increased coronary flow at all CPP values at all administered doses. Tadalafil led to an increase in the NO levels, but a statistically significant NO release increase was found only at the highest dose and highest CPP. Tadalafil did not significantly affect the release of O²⁻. After inhibiting the nitrite oxide synthase system by L-NAME, tadalafil-induced changes in cardiac flow and NO levels were reversed. L-NAME administration had no pronounced effect on the O²⁻ release. <b><i>Conclusion:</i></b> Tadalafil causes changes in the heart vasculature in a dose-dependent manner. It does not lead to a significant increase in the production of superoxide anion radicals.

Astragalus mongholicus Bunge Water Extract Exhibits Anti-inflammatory Effects in Human Neutrophils and Alleviates Imiquimod-Induced Psoriasis-Like Skin Inflammation in Mice

Neutrophils are the primary immune cells in innate immunity, which are related to various inflammatory diseases. Astragalus mongholicus Bunge is a Chinese medicinal herb used to treat various oxidative stress-related inflammatory diseases. However, there are limited studies that elucidate the effects of Astragalus mongholicus Bunge in human neutrophils. In this study, we used isolated human neutrophils activated by various stimulants to investigate the anti-inflammatory effects of Astragalus mongholicus Bunge water extract (AWE). Cell-free assays were used to examine free radicals scavenging capabilities on superoxide anion, reactive oxygen species (ROS), and nitrogen-centered radicals. Imiquimod (IMQ) induced psoriasis-like skin inflammation mouse model was used for investigating anti-psoriatic effects. We found that AWE inhibited superoxide anion production, ROS generation, and elastase release in human neutrophils, which exhibiting a direct anti-neutrophil effect. Moreover, AWE exerted a ROS scavenging ability in the 2,2’-Azobis (2-amidinopropane) dihydrochloride assay, but not superoxide anion in the xanthine/xanthine oxidase assay, suggesting that AWE exhibited anti-oxidation and anti-inflammatory capabilities by both scavenging ROS and by directly inhibiting neutrophil activation. AWE also reduced CD11b expression and adhesion to endothelial cells in activated human neutrophils. Meanwhile, in mice with psoriasis-like skin inflammation, administration of topical AWE reduced both the affected area and the severity index score. It inhibited neutrophil infiltration, myeloperoxidase release, ROS-induced damage, and skin proliferation. In summary, AWE exhibited direct anti-inflammatory effects by inhibiting neutrophil activation and anti-psoriatic effects in mice with IMQ-induced psoriasis-like skin inflammation. Therefore, AWE could potentially be a pharmaceutical Chinese herbal medicine to inhibit neutrophilic inflammation for anti-psoriasis.

Research of corrosion fracture of D16t and AMg6 aluminum alloys exposed to microscopic fungi

This paper presents an experimental study of biocorrosion of D16T and AMg6 aluminum alloys. The determining role of reactive oxygen species in aluminum biocorrosion by a consortium of molds has been shown. A model is proposed, according to which the initiators of corrosion damage to the metal surface are superoxide anion radical and hydrogen peroxide released during the life of micromycetes. It is assumed that the initiation and development of biocorrosion occurs, among other things, as a result of the process of reductive activation of oxygen and the Fenton decomposition of hydrogen peroxide. A conclusion is made about the mechanism of the occurrence of intergranular and pitting corrosion of aluminum alloys interacting with microscopic fungi.

Constituents from the Fruiting Bodies of Trametes cubensis and Trametes suaveolens in Vietnam and Their Anti-Inflammatory Bioactivity

It is reported that various fungi have been used for medicine and edible foods. The tropical Trametes genus is popular and well-known in Vietnam for its health effects and bioactivities. In this study, the fruiting bodies of the edible fungi T. cubensis and T. suaveolens were collected in Vietnam. The preliminary bioactivity screening data indicated that the methanol extracts of the fruiting bodies of T. cubensis and T. suaveolens displayed significant inhibition of superoxide anion generation and elastase release in human neutrophils. Therefore, the isolation and characterization were performed on these two species by a combination of chromatographic methods and spectrometric analysis. In total, twenty-four compounds were identified, and among these (1–3) were characterized by 1D-, 2D-NMR, and HRMS analytical data. In addition, the anti-inflammatory potentials of some purified compounds were examined by the cellular model for the inhibition of superoxide anion generation and elastase release in human neutrophils. Among the isolated compounds, (5,14), and (19) displayed significant anti-inflammatory potential. As the results suggest, the extracts and isolated compounds from T. cubensis and T. suaveolens are potential candidates for the further development of new anti-inflammatory lead drugs or natural healthy foods.